Transition from toroidal to slab temperature gradient driven modes

Abstract
In the local approximation the electrostatic dispersion relation for the (ion or electron) temperature gradient driven modes is solved retaining the full guiding‐center resonance condition ω=kv+k⋅vD (v2,v2). Increase of the slab‐to‐toroidal ratio parameter kvT/kvD is shown to directly increase the threshold value of the temperature‐to‐density gradient parameter ηc. Therefore, the local anomalous heat flux has a strong dependence on the safety factor q when k∼1/qR.